1. Field of the Invention
The present invention relates to a design method and design system for a vehicular lamp used for vehicles such as an automobile and relates to a program for allowing a computer to execute designing of the vehicular lamp and a computer-readable record medium recording the program.
2. Related Background Art
Regarding a vehicular lamp, besides (1) conditions from aspects related to functions and performance as a lamp, because of its use in a state of being attached to a vehicle such as an automobile and the like, restriction conditions such as (2) conditions from aspects related to its shape (shape restriction conditions), (3) conditions from aspects related to its external appearance (appearance restriction conditions) and the like are imposed thereon. Therefore, in designing the lamp, it is required to realize a lamp in which the restriction conditions from given aspects of the shape and external appearance are satisfied and performance conditions thereof are optimized.
As the conditions from the aspect of performance, there are conditions from aspects of an optical performance such as a luminous intensity distribution pattern and the like, a structural performance, a thermal performance and the like, the conditions being required according to types of the lamp as the function of the vehicular lamp. Moreover, regarding the restriction conditions from the aspect of a car body, as the shape restriction conditions, there are conditions related to volume and shape of a lamp housing portion provided in the car body, to a shape of a lens outer surface of the lamp, the shape being continuous with other portions of the car body, and the like. Moreover, as the appearance restriction conditions, there are conditions related to a harmony between the external appearance thereof and an external appearance of the other portions of the car body, to a design of the car body and the like.